Frequency of JAK2V617F and associated alterations on chromosome 9. (A) Diagrams represent matched and unmatched MPN cases in chronic versus blast phase. Indicated are frequencies of JAK2V617F and association to 9p duplication (dupl)/trisomy 9 or 9pCNN-LOH. Data and statistical evaluation for underlying MPN subgroups are shown in supplemental Table 3. (B) CNAG software represents duplication (red) and CNN-LOH (green) on 9p detected in 11 patients with matched samples (chronic MPN vs MPN-blast phase). In addition, allele-specific PCR for the detection of JAK2V617F was performed in these samples. Arrows indicate 2 MPN patients who were initially positive for JAK2V617F in association with 9p imbalances; leukemic transformation was accompanied with loss of JAK2V617F and a normal chromosome 9.